JP5783226B2 - Printing apparatus and printing method - Google Patents

Description

  The present invention relates to a printing apparatus and a printing method.

  As one of printing apparatuses, an ink jet printer (hereinafter referred to as a printer) having a head that ejects ink from a nozzle to a medium is known. In recent years, images have been printed not only on paper media but also on transparent films and the like. When printing an image on a transparent film, the color development of the image can be improved by printing the background image with white ink. Further, a method for inspecting a non-ejection nozzle based on reflected light or transmitted light with respect to an image printed on a transparent film has been proposed (see, for example, Patent Document 1).

JP 2008-87287 A

When printing a background image and a color image with white ink on a transparent film, the background image is printed first on the transparent film, and the color image is printed on the background image. In some printers, a color image is first printed, and a reverse printing mode in which a background image is printed on the color image can be selected. In such a printer, in addition to a color image (main image), for example, an additional image such as a non-ejection test pattern may be printed over a background image using white ink. In this case, if the additional image is printed in accordance with the print mode of the main image, the content of the additional image cannot be confirmed, for example, a background image is interposed between the sensor that reads the additional image and the additional image. There has occurred.
Therefore, an object of the present invention is to make it possible to confirm the contents of an additional image.

A main invention for solving the above-described problems is a printing apparatus that prints an image on a medium by discharging ink from a nozzle according to a set mode, and a first setting unit that sets a print mode of the main image A surface printing mode for printing the main image on the background image after printing the background image on the medium, and the background on the main image after printing the main image on the medium. A first setting unit for setting any one of the reverse printing modes for printing an image, and a second setting unit for setting a printing mode for an additional image to be printed in association with the printing of the main image. Then, after printing the background image for the additional image on the medium, a surface printing mode for printing the additional image on the background image for the additional image, and after printing the additional image on the medium, The additional image on the additional image Of reverse printing mode for printing a background image of use, a printing apparatus, characterized in that it comprises a second setting unit, a for setting either one.
Further, the printing apparatus of the present invention is capable of executing, as printing modes, a front printing mode for printing an image after printing a background image on a medium and a back printing mode for printing a background image after printing an image on a medium. And the control unit determines the printing mode based on whether the printing surface of the medium is wound on the outer side or the printing surface of the medium is wound on the inner side. The printing apparatus characterized by this may be used.
Other features of the present invention will become apparent from the description of this specification and the accompanying drawings.

1 is an overall configuration block diagram of a printing system. FIG. 2A is a schematic sectional view of the printer, and FIG. 2B is a diagram showing the arrangement of the heads in the head unit. It is a figure explaining the printed matter mentioned as an example in this embodiment. It is a figure explaining the printing mode of a main printed matter and an additional printed matter. It is a flow in which the main image setting unit sets the print mode of the main printed matter. FIG. 6A is a flowchart in which the additional image setting unit sets the print mode of the additional printed material, and FIG. 6B is a diagram illustrating the difference in the print position of the additional image due to the difference in the winding method of the continuous medium. FIG. 10 is a diagram for explaining another printing example when the printing mode of the main image and the additional image are different. It is a figure which shows the head which the printer of 2nd Embodiment has. It is a figure which shows the surface printing mode and back printing mode in the printer of 2nd Embodiment. It is a figure which shows another printing method. 11A and 11B are diagrams illustrating a printing method in which the nozzles for the background image are different between the main printed material and the additional printed material. It is a figure which shows the surface printing mode and back printing mode in the printer of 2nd Embodiment. It is a figure which shows another printing method.

=== Summary of disclosure ===
At least the following will become apparent from the description of the present specification and the accompanying drawings.

That is, a printing apparatus that discharges ink from nozzles according to a set mode and prints an image on a medium, and is a first setting unit that sets a print mode of a main image, and a background on the medium A front printing mode for printing the main image on the background image after printing an image, and a back printing mode for printing the background image on the main image after printing the main image on the medium. A first setting unit that sets one of the second setting unit and a second setting unit that sets a print mode of an additional image to be printed in association with printing of the main image, the additional image on the medium A surface printing mode for printing the additional image on the background image for the additional image after printing the background image for printing, and for the additional image on the additional image after printing the additional image on the medium. Backprint to print background image Of over-de, a printing apparatus, characterized in that it comprises a second setting unit for setting either one, the.
According to such a printing apparatus, it is possible to print a printed matter in which the content of the additional image can be confirmed.

In this printing apparatus, when the additional image is an image read by a sensor, the second setting unit sets a printing mode of the additional image between the sensor and the additional image as a background for the additional image. Set the print mode to print an image without any image.
According to such a printing apparatus, the sensor can read the additional image.

In this printing apparatus, when the medium after printing is wound in a roll shape and the printing surface of the medium is wound outside, the second setting unit is configured to print the additional image in a printing mode. Is set to the front printing mode, and the second setting unit sets the printing mode of the additional image to the back printing mode when the printing surface of the medium is wound inside.
According to such a printing apparatus, the content of the additional image can be confirmed from the outside of the medium wound up in a roll shape.

The printing apparatus includes a user selection unit that allows a user to select a printing mode for the main image and a printing mode for the additional image.
According to such a printing apparatus, the content of the additional image can be confirmed in accordance with the user's application.

In this printing apparatus, the relative position of the medium and the nozzle is relatively moved in one direction, and ink is ejected from the nozzle to print an image on the medium. When the printing mode of the main image and the printing mode of the additional image are different among the reverse printing modes, before printing the additional image or the background image for the additional image, the relative position of the medium and the nozzle is set to Relative movement in the other direction of the specified direction.
According to such a printing apparatus, an image can be printed according to each printing mode, the nozzle for printing the main image and the additional image can be made the same, and the background image for the main image and the additional image can be used. The same nozzle can be used for printing the background image.

In this printing apparatus, a margin amount of the background image for the additional image with respect to the additional image is set larger than a margin amount of the background image with respect to the main image.
According to such a printing apparatus, the additional image and the background image for the additional image can be printed in an overlapping manner.

In this printing apparatus, the relative position of the medium and the nozzle is relatively moved in one direction, and ink is ejected from the nozzle to print an image on the medium. When the printing mode of the main image and the printing mode of the additional image are different among the back-printing modes, they are located on the one direction side and the other direction side of the predetermined direction with respect to the nozzle that prints the main image and the additional image. Among the nozzles to be used, one nozzle is used as a nozzle for printing the background image, and the other nozzle is used as a nozzle for printing the background image for the additional image.
According to such a printing apparatus, an image can be printed according to each printing mode without relatively moving the nozzle and the medium in the opposite directions, and the nozzle for printing the main image and the additional image is made the same. Can do.

In this printing apparatus, the main image is printed with a first ink, and the background image is printed with the first ink and the second ink.
According to such a printing apparatus, a background image of a desired color can be printed.

The first setting unit prints a background image on the medium and then prints the main image on the background image; and after printing the main image on the medium, The main image and the background image are set according to the mode set by the first setting unit, and any one of the reverse printing modes for printing the background image is set as the main image print mode. And the second setting unit prints the additional image on the background image for the additional image after printing the background image for the additional image to be printed in relation to the printing of the main image on the medium. Any one of a front printing mode for printing an image and a back printing mode for printing a background image for the additional image on the additional image after printing the additional image on the medium is performed. Set the print mode to Printing method characterized in that it comprises a possible serial second setting unit said print a background image for the additional image and the additional image in accordance with the mode set, the.
According to such a printing method, it is possible to print a printed matter in which the content of the additional image can be confirmed.

=== First Embodiment ===
<< About the printing system >>
As an example of a printing apparatus, an inkjet printer (hereinafter referred to as printer 1) is taken as an example, and an embodiment will be described using a printing system in which the printer 1 and the computer 60 are connected.

  FIG. 1 is an overall configuration block diagram of the printing system, FIG. 2A is a schematic cross-sectional view of the printer 1, and FIG. 2B is a diagram illustrating an arrangement of the short heads 311 in the head 31. The computer 60 is communicably connected to the printer 1 and outputs print data corresponding to the image to be printed to the printer 1 in order to cause the printer 1 to print an image. The computer 60 is installed with a program (printer driver) for converting image data output from the application program into print data. This printer driver is recorded on a recording medium (computer-readable recording medium) such as a flexible disk FD or a CD-ROM. Alternatively, the printer driver may be downloaded to the computer 60 via the Internet.

  The printer 1 that has received the print command and print data from the computer 60 controls each unit by the controller 10 to form an image on the continuous medium S. Further, the detector group 50 monitors the situation in the printer 1, and the controller 10 controls each unit based on the detection result.

  The controller 10 is a control unit for controlling the printer 1. The interface unit 11 is for transmitting and receiving data between the computer 60 and the printer 1. The CPU 12 is an arithmetic processing unit for controlling the entire printer 1. The memory 13 is for securing an area for storing a program of the CPU 12, a work area, and the like. The CPU 12 controls each unit by the unit control circuit 14.

  The transport unit 20 is for transporting the continuous medium S. Conveying rollers 21A and 21B and a conveying belt 22 are provided, and the continuous medium S is conveyed at a predetermined conveying speed in the conveying direction during printing. In order to prevent displacement of the medium during printing, the medium S may be sucked from the lower side and the medium S may be vacuum-adsorbed to the transport belt 22.

  The head unit 30 has a plurality of heads 31 for ejecting ink onto a medium. As shown in FIG. 2A, a plurality of heads 31 are arranged along the medium conveyance direction. In order from the upstream side in the transport direction, a first white head 31 (W1) that discharges white ink, a yellow head 31 (Y) that discharges yellow ink, a magenta head 31 (M) that discharges magenta ink, and cyan. A cyan head 31 (C) that ejects ink, a black head 31 (K) that ejects black ink, and a second white head 31 (W2) that ejects white ink are arranged.

  As shown in FIG. 2B, a plurality of short heads 311 are arranged in the paper width direction on the lower surface of each head 31, and a plurality of nozzles serving as ink ejection units are provided on the lower surface of the short head 311. A plurality of nozzles are arranged at a predetermined interval D in the paper width direction on the lower surface of the short head 311, and the respective short heads 311 are arranged so that the nozzle interval between adjacent short heads 311 is also the predetermined interval D. Therefore, on the lower surface of the head 31, a plurality of nozzles are arranged at predetermined intervals D in the paper width direction. Each nozzle is provided with a pressure chamber (not shown) containing ink, and a drive element (for example, a piezo element) for discharging the ink by changing the capacity of the pressure chamber. When the drive signal is applied to the drive element, the drive element is deformed, and the pressure chamber expands / contracts along with the deformation, and ink is ejected.

  In this embodiment, “ultraviolet curable ink” that is cured by being irradiated with ultraviolet rays is used as the ink. An ultraviolet curable ink (hereinafter referred to as ink) is prepared by adding an auxiliary agent such as an antifoaming agent or a polymerization inhibitor to a mixture of a vehicle, a photopolymerization initiator and a pigment. The vehicle is prepared by adjusting the viscosity of a photopolymerization-curing oligomer, monomer or the like with a reactive diluent. The ink includes both water-based ink and oil-based ink.

The ultraviolet irradiation unit 40 has an irradiator (a temporary irradiator 41 and a main irradiator 42) for irradiating the ultraviolet curable ink discharged from the head 31 onto the medium by irradiating it with ultraviolet rays. Each of the irradiators 41 and 42 includes a lamp (for example, a metal halide lamp or an LED) that cures by irradiating the ultraviolet curable ink with ultraviolet rays. By adjusting the irradiation amount of ultraviolet rays (irradiation intensity (mJ / cm ² ), the number of irradiations, etc.) by the irradiators 41 and 42, the ultraviolet curable ink may be completely cured or not completely cured. it can. A temporary irradiator 41 is provided between the heads 31 that eject different color inks. The main irradiator 42 is provided on the most downstream side in the transport direction. The temporary irradiator 41 irradiates ultraviolet rays whose irradiation intensity is weaker than that of the main irradiator 42. Therefore, the ultraviolet curable ink discharged from the head 31 to the medium S is irradiated with ultraviolet rays so that it is not completely cured by the provisional irradiator 41 (semi-cured state), and is completely cured by the main irradiator 42. Ultraviolet rays are irradiated so as to obtain a completed state (fully cured state). A reading sensor 51 is provided further downstream than the main irradiator 42. Since the reading sensor 51 (sensor) is provided on the head 31 side (upward) with respect to the continuous medium S, the printing surface of the continuous medium S and the reading sensor 51 face each other.

  In such a printer 1, when receiving the print data, the controller 10 transports the continuous medium S on the transport belt 22 without stopping at a constant speed. At that time, each head 31 and the irradiators 41 and 42 face the continuous medium S, and ultraviolet curable ink is ejected from each head 31 to the medium, and the ultraviolet curable ink is cured by the irradiators 41 and 42. . As a result, an image is printed on the medium. And the continuous medium S after printing is wound up in roll shape by the winding unit 70, as shown to FIG. 2A. The winding unit 70 of the present embodiment changes the winding direction so that the winding surface (outer winding) has a printing surface located outside as shown in the upper diagram of FIG. 2A and the lower diagram of FIG. 2A. In addition, it is possible to implement two types of winding molds of the winding method (inner winding) in which the printing surface is located inside.

<< About print images >>
FIG. 3 is a diagram for explaining a printed matter exemplified in this embodiment. A “main print” in which a “main image” printed with four color inks (including K) and a “background image” printed with white ink are superimposed, and an “additional image” printed with four color inks It is assumed that two types of printed matter, “additional printed matter” on which “background image” printed with white ink is superimposed, are printed. The continuous medium S used in this embodiment is a transparent medium (eg, a transparent resin film). Therefore, by overlaying the white background image on the image (main image / additional image) to be printed with the four color inks, the color development of the color image is improved and the opposite side of the printed material is prevented from being seen through. it can. In FIG. 3, the additional printed material is printed at a position upstream of the main printed material in the transport direction. However, the present invention is not limited to this, and the additional printed material may be printed at a position downstream of the main printed material in the transport direction. 3 shows a state in which only one main print is formed on the continuous medium S, one additional print is formed on one main print, but the present invention is not limited to this. . For example, when a large number of main prints are continuously printed on the continuous medium S, one additional print may be printed for each predetermined number of main prints.

  The main image is an image instructed to be printed by the user. On the other hand, the additional image is an image indicating information regarding printing of the main image. In FIG. 3, as the “additional image”, a non-ejection inspection pattern for four color nozzles (YMCK) is formed. The non-ejection inspection pattern is composed of dot rows formed by the four color (YMCK) nozzles used for printing the main image. The presence or absence of ejection from the nozzle is determined depending on whether or not the dot row is normally formed by each nozzle. In this way, by printing the non-ejection inspection pattern of the nozzle used to print the main image together with the main image, the user can check whether the main image is printed without the non-ejection nozzle. Can do. The non-ejection inspection pattern also plays a role of quality assurance indicating that the main image is printed in a normal state without non-ejection nozzles. In FIG. 3, in addition to the non-ejection inspection pattern, the lot number of the main image is printed as an additional image. Note that the type of the additional image is not limited to this, and as the information related to the printing of the main image, for example, the serial number of the printer 1 that performed the printing, or information indicating the type of the medium or the main image may be printed. In this embodiment, since the main printed matter is printed on the continuous medium S, the main printed matter may be cut out from the continuous medium S in a later step. As a mark (additional image) indicating the cutout position at that time, a mark such as an L-shape or a cross (so-called registration mark) may be printed at the four corners of the main image or at two diagonal positions.

  Further, the additional image may be read visually by the user, or may be read by a sensor of the reading sensor 51 shown in FIG. 2 or an external device (for example, a main printing material cutting device). For this reason, in FIG. 3, the lot number is printed as a number, but this is not limiting, and the additional image may be a pattern such as a barcode.

  The additional image may be printed in association with the printing of the main image. For example, information related to printing may be printed, or information related to printing may be printed. For example, what is printed in order to confirm the print contents and the print state can be mentioned. Further, the time when the additional image is printed may be any time before or after printing the main image or during the printing of a plurality of main images. Further, it may be printed according to a user instruction, or may be instructed by the user to confirm the print content and print state of the main image.

<< About print mode >>
FIG. 4 is a diagram for explaining the printing mode of the main printed matter and the additional printed matter. In the printer 1 of the present embodiment, when a color image (main image / additional image) and a white background image are printed on a transparent medium (transparent film or the like), the “front printing mode” and “back side” It is assumed that printing can be performed by selecting two types of printing modes “printing mode”. In the front printing mode, as shown in the upper diagram of FIG. 4, a background image is first printed on a predetermined area on the medium, and a color image (main image or additional image) is printed on the background image. For this reason, a printed matter printed in the front printing mode will see a color image from the printing surface. On the other hand, in the reverse printing mode, as shown in the lower diagram of FIG. 4, a color image (main image or additional image) is first printed on a predetermined area on the medium, and a background image is printed on the color image. . Therefore, a printed matter printed in the reverse printing mode sees a color image through the medium.

  By the way, in the printer 1 of the present embodiment, in order to implement the front printing mode and the back printing mode, as shown in FIG. 2, the heads 31 (W1, W2) that discharge white ink to the most upstream side and the most downstream side in the transport direction. ) Are provided. That is, the white heads 31 (W1, W2) are provided on the upstream side and the downstream side, respectively, in the transport direction of the head 31 that discharges four-color ink (YMCK). By doing so, in the front printing mode, the background image is printed first in a predetermined area on the medium by the first white head 31 (W1) on the upstream side, and on the background image by the central four-color head 31 (YMCK). Color images can be printed. On the other hand, in the reverse printing mode, a color image is first printed in a predetermined area on the medium by the central four-color head 31 (YMCK), and a background image is formed on the color image by the second white head 31 (W2) on the downstream side. Can be printed.

<< Print mode settings >>
FIG. 5 is a flow in which the main image setting unit 141 sets the print mode of the main printed matter. As shown in FIG. 1, in the printer 1 of the present embodiment, a “main image setting unit 141 (first setting unit)” is provided in the controller 10. For main prints, the print mode is determined by user settings. In the printing system of the present embodiment, print data is created by a printer driver in the computer 60 connected to the printer 1. For this reason, when the printer driver is instructed to print a color image and a white background image on top of each other, or when a transparent medium is set as a medium for printing an image, the printer driver “prints” on the display of the computer 60 or the like. A mode setting window (not shown) "is displayed. The window allows the user to set either the front printing mode or the back printing mode. Then, the printer driver transmits print information indicating the print mode set by the user to the printer 1 together with the created print data.

  After that, as shown in FIG. 5, the main image setting unit 141 determines whether the print mode set by the user is the front print mode based on the received print information (S001). When the print mode set by the user is the front print mode (S001 → Y), the main image setting unit 141 sets the print mode to the front print mode (S002). In this case, the main image setting unit 141 determines the head 31 used to print the background image as the first white head 31 (W1), and transmits the print data of the background image to the first white head 31 (W1). (S003). By doing so, the background image is first printed in a predetermined area on the medium by the first white head 31 (W1) on the upstream side in the transport direction, and the four-color head 31 (YMCK) in the center in the transport direction is printed on the background image. Color images can be printed.

  On the other hand, when the printing mode set by the user is not the front printing mode (S001 → N), the main image setting unit 141 sets the printing mode to the back printing mode (S004). In this case, the main image setting unit 141 determines the head 31 used for printing the background image as the second white head 31 (W2), and transmits the print data of the background image to the second white head 31 (W2). (S005). By doing so, a color image is first printed in a predetermined area on the medium by the four-color head 31 (YMCK) in the central portion in the transport direction, and on the color image by the second white head 31 (W2) downstream in the transport direction. A background image can be printed.

  In this way, the printer 1 can print the main printed material in the printing mode set by the user. The main image setting unit 141 may only set the print mode for printing the main print, and the white ink head used by the other control units based on the print mode set by the main image setting unit 141. 31 may be determined, or the print data for the background image may be transmitted to the white ink head 31 to be used.

  In this embodiment, as shown in FIG. 3, an additional printed material is printed in addition to the main printed material. Here, it is assumed that the additional printed material can be printed only in the same print mode as the main printed material. That is, it is assumed that the printing mode for the main printed material and the printing mode for the additional printed material cannot be set independently. For example, when the user sets the main printed material to be printed in the reverse printing mode, the additional printed material is also printed in the same reverse printing mode. In the printer 1 shown in FIG. 2, an additional image reading sensor 51 is provided on the head 31 side (printing surface side). For this reason, when the additional printed matter is printed in the reverse printing mode, a background image is interposed between the reading sensor 51 and the additional image, and the reading sensor 51 cannot read the additional image. That is, if the background image is printed on the reading sensor 51 side rather than the additional image as a result of printing the print mode of the additional printed material in accordance with the printing mode of the main printed material, the reading sensor 51 reads the content of the additional image. It becomes impossible to do. In other words, if the reading sensors 51 are provided on both the printing surface side (head side) and the conveyance belt side in accordance with the positional relationship between the additional image and the background image in the front printing mode and the back printing mode, costs increase. End up.

  Moreover, in this embodiment, as shown in FIG. 2, the continuous medium S is wound up in a roll shape. Therefore, for example, when the continuous medium S is wound up (outside winding) so that the printing surface (the head side surface) is outside as shown in the upper diagram of FIG. When printing is performed in the mode, the background image is positioned above the print surface relative to the additional image, so that the content of the additional image cannot be confirmed from the outside of the roll-up medium.

  Therefore, an object of the present embodiment is to make it possible to confirm the content of the additional image by the reading sensor 51 or to confirm the content of the additional image from the outside of the roll-shaped medium. That is, the purpose is to print the additional image so that the content of the additional image can be confirmed. For this purpose, in the printer 1 of the present embodiment, as shown in FIG. 1, the controller 10 is provided with both the main image setting unit 141 and the additional image setting unit 142 (second setting unit), and the print mode and the addition of the main printed matter. The print mode of the printed material can be set independently. An additional image reading sensor may be provided on the opposite side of the head 31 (opposite the printing surface) with respect to the medium. In this case, the additional sensor can read the additional image by printing the additional printed material in the reverse printing mode.

  6A is a flow in which the additional image setting unit 142 sets the print mode of the additional printed material, and FIG. 6B is a diagram illustrating a difference in the print position of the additional image due to a difference in the winding method of the continuous medium S. As illustrated in FIG. 6A, the additional image setting unit 142 determines whether the additional image to be printed is an image read by the reading sensor 51 based on the print information (or default print setting) received from the computer 60. Is determined (S101). In the printer 1 of the present embodiment, since the reading sensor 51 is positioned on the head 31 side (printing surface side) (FIG. 2), when the additional image is read by the reading sensor 51 (S101 → Y), the additional image setting unit 142 is added. The print mode of the printed material is set to the front print mode (S102). In this case, the additional image setting unit 142 determines the head 31 used for printing the background image for the additional image as the first white head 31 (W1), and sets the print data of the background image for the additional image as the first data. The white head 31 (W1) is transmitted (S103). By doing so, the background image is first printed in a predetermined area on the medium by the first white head 31 (W1), and then the additional image is printed on the background image by the four-color head 31 (YMCK). Since the additional image is positioned closer to the reading sensor 51 than the background image, the reading sensor 51 can read the content of the additional image.

  In the printed matter shown in FIG. 3, two types of “non-ejection inspection pattern” and “lot number” are printed as additional images. When printing a plurality of additional images as described above, if at least one additional image of the plurality of additional images is an image read by the reading sensor 51, the additional image setting unit 142 sets the print mode of the additional printed matter. Set the front print mode.

  On the other hand, when the additional image is an image that cannot be read by the reading sensor 51 (S101 → N), the additional image setting unit 142 determines the print mode according to the winding method of the continuous medium S. For example, the left diagram of FIG. 6B shows a state in which the main printed matter is printed in the surface printing mode (printing surface side) and the continuous medium S is wound up (so that the printing surface is on the outside). When the continuous medium S is externally wound, since the printing surface is located on the outside, the medium surface visible from the outside at the end of winding of the continuous medium S is the printing surface. Therefore, when the continuous medium S is externally wound (S104 → Y), the additional image setting unit 142 sets the print mode of the additional printed matter to the front printing mode (S102). By doing so, since the additional image is positioned outside the roll-shaped medium S than the background image, the content of the additional image can be confirmed even after the continuous medium S is rolled up. For example, even if there are a large number of printed roll-shaped media, when the additional image indicates the type of the main image, it is possible to easily confirm which main image is printed on which roll-shaped medium.

  On the other hand, the right diagram in FIG. 6B shows a state in which the main printed matter is printed in the surface printing mode (printing surface side) and the continuous medium S is wound inwardly (so that the printing surface is on the inner side). . When the continuous medium S is wound inward, the printing surface is located on the inner side, so that the medium surface visible from the outside at the end of winding of the continuous medium S is the surface opposite to the printing surface side. Therefore, when the continuous medium S is wound inward (S104 → N), the additional image setting unit 142 sets the printing mode of the additional printed material to the reverse printing mode (S105). By doing so, the additional image can be seen from the outside of the roll-shaped medium S through the medium, and the content of the additional image can be easily confirmed even after the continuous medium S is wound up in a roll shape. .

  As described above, in the present embodiment, the printer 1 (controller 10) is provided with the main image setting unit 141 and the additional image setting unit 142, and the main image (main print product) print mode and the additional image (addition print product) print mode are set. Set independently. By doing so, the print mode of the additional image is set according to the position of the reading sensor 51 so that the reading sensor 51 can read the additional image, and the content of the additional image is also confirmed from the outside of the roll-shaped continuous medium S. For example, the print mode of the additional image can be set in accordance with the outer medium surface when the continuous medium S is wound. That is, in the present embodiment, it is possible to form a printed matter in which the content of the additional image can be confirmed.

  Note that setting the print mode of the main image (main print product) and the print mode of the additional image (additional print product) independently means that when the main image and the additional image are printed on the same side with respect to the background image, In some cases, the main image and the additional image are printed on different sides of the background image. 5 and 6A, the white heads 31 (W1, W2) for printing the background images of the respective images are determined according to the print modes of the main image and the additional image. For this reason, if the printing modes of the main image and the additional image are different, both the first white head 31 (W1) and the second white head 31 (W2) are used. For example, as shown in the right diagram of FIG. 6B, when printing the main printed material in the front printing mode and printing the additional printed material in the back printing mode, the background image for the main image is printed by the first white head 31 (W1) and added. The background image for the image is printed by the second white head 31 (W2).

  In the flow of FIG. 6A, when the additional image is not read by the reading sensor 51 (S101 → N), the print mode of the additional image (additional printed matter) is determined by the winding method of the continuous medium S (S104). However, the present invention is not limited to this. For example, the user may set the print mode of the additional image. For this purpose, for example, when a printer driver installed in the computer 60 is instructed to print an additional image on a transparent medium, a “additional image print mode setting window (not shown)” is displayed on the display of the computer 60 or the like. May be displayed. In this way, the printer driver may allow the user to select the print mode for the main image and the print mode for the additional image. By doing so, the user can make the print mode of the main image and the additional image the same or different depending on the application, and can print the contents of the additional image in a confirmable manner. In this case, the UI (user interface) of the printer driver corresponds to the user selection unit, and the printing system in which the printer 1 and the computer 60 in which the printer driver is installed is connected corresponds to the printing apparatus. However, the present invention is not limited to this, and the controller 60 of the printer 1 may serve as a user selection unit. In this case, the printer 1 alone corresponds to the printing apparatus.

  Further, in the case of a printer in which the winding method of the continuous medium S is not changeable like the printer 1 of the present embodiment (FIG. 2), when the additional image is not read by the reading sensor 51, the continuous medium S is fixed. The print mode of the additional image is automatically determined depending on the winding method. On the contrary, if the printer 1 does not have the reading sensor 51, the print mode of the additional image may be determined only based on the winding method of the continuous medium S, or an external device (for example, a main print cutout device). The print mode of the additional image may be determined based on the reading sensor, or the user may set the print mode of the additional image.

<< About other print examples >>
FIG. 7 is a diagram for explaining another example of printing when the printing modes of the main image and the additional image are different. In the flow of FIG. 5 and FIG. 6A described above, the white head 31 (W1, W2) for printing the background image of each image is determined according to each print mode of the main image and the additional image, but this is not restrictive. . Even when the printing mode of the main image and the additional image is different, one of the two white heads 31 (W1, W2) may be used. By doing so, it is not necessary to perform the cleaning operation on the white head 31 that is not used out of the two white heads 31 (W1, W2), and ink consumption other than printing can be suppressed.

  For example, in FIG. 7, it is assumed that the white head 31 (W) to be used is determined according to the print mode of the main image. In FIG. 7, in order to print the main printed material in the front printing mode and print the additional printed material in the back printing mode, the first white head 31 (W1) is used and the second white head 31 (W2) is not used. Become. In this case, the main printed matter is applied to the first white head 31 (W1) with respect to a predetermined region of the continuous medium S that is transported from the upstream side (one side) to the downstream side (the other side) in the transport direction (predetermined direction). The background image can be printed first, and then the main image can be printed on the background image by the four-color ink head 31 (YMCK). On the other hand, the additional printed matter is printed by the first white head 31 positioned upstream of the four-color ink head 31 after the additional image is first printed by the four-color ink head 31. A background image must be printed on top. For this reason, after the additional image is printed with the four-color ink head, the continuous medium S is reversely fed from the downstream side to the upstream side in the transport direction, and the medium area on which the additional image is printed and the first white head W1 again. The background image is printed on the additional image with the two facing each other.

  As described above, when one of the two white heads 31 (W1, W2) positioned on the upstream side and the downstream side in the transport direction is used, and when the print mode of the main print product and the additional print product is different, When printing a color image, it is necessary to transport the continuous medium S in the reverse direction. The position control (conveyance amount control) of the medium is controlled based on, for example, the rotation angles of the conveyance rollers 21A and 21B. For this reason, if the medium is transported in the reverse direction (from downstream to upstream) and then transported again in the forward direction (from upstream to downstream), an error is likely to occur in the position control of the medium. As a result, the print position of the previously printed image (additional image in FIG. 7) and the print position of the later printed image (background image in FIG. 7) are likely to shift. That is, there is a possibility that the image quality is deteriorated in the printed matter in which the continuous medium S is reversely fed and printed. Therefore, as shown in FIG. 7, it is preferable to determine the white head 31 (W) to be used according to the print mode of the main image. By doing so, the main printed material can be printed without reverse feeding of the continuous medium S, and can be printed with high image quality. On the other hand, the additional printed material is printed with reverse feeding of the continuous medium S. There is a possibility, but there is no problem because it is an additional printed matter.

  Further, since the additional printed matter is printed by feeding back the continuous medium S before printing the additional image or the background image for the additional image, the position of the additional image and the background image is likely to be shifted. For this reason, the amount of margin of the background image for the additional image (3 mm in FIG. 7) is preferably larger than the amount of margin of the background image for the main image (0.3 mm in FIG. 7). By doing so, it is possible to print the additional printed matter by reversely feeding the continuous medium S, and the additional image and the background image can be overlapped and printed even if the printing positions of the additional image and the background image are likely to be shifted. In addition, there is no problem even if the amount of margin of the background image is large if it is an additional printed matter. In other words, since the main printed matter can be printed without reversely feeding the continuous medium S, the printing position of the main image and the background image is difficult to shift, and the amount of margin of the background image can be reduced.

  Further, in FIG. 3, only the non-ejection inspection pattern of the four-color ink (YMCK) nozzle is formed, but not limited to this, the non-ejection inspection pattern of the white nozzle is printed as an additional image as shown in FIG. May be. Since the white ink is more visible on a transparent medium than other color inks (YMCK), the non-ejection test pattern of the white nozzle does not have to be printed over the background image.

  In addition, a background image of other color ink (for example, black ink) may be superimposed and printed on the non-ejection inspection pattern of the white nozzle with white ink. For example, as shown in FIG. 7, when the first white head 31 (W1) corresponding to the print mode of the main print product is used and the print modes of the main print product and the additional print product are different, the four-color ink head 31 ( YMCK), the non-ejection test pattern is printed, and then the continuous medium S is fed backward, and the background image is printed by the upstream first white head 31 (W1). On the other hand, the non-ejection test pattern of the white nozzle is printed first by the first white head 31 (W1) on the upstream side and the black medium while the continuous medium S is conveyed downstream. The head 31 (K) can print a black background image on the non-ejection inspection pattern of the white nozzle. That is, unlike the non-ejection test pattern of the four-color ink nozzles, the non-ejection test pattern of the white nozzles does not need to reversely feed the continuous medium S.

  Further, when the print modes of the main print product and the additional print product are different, the background image can be shared and the main print product and the additional print product can be printed at the same position on the continuous medium S. In this case, the consumption of the continuous medium S can be reduced. Therefore, if the main image setting unit 141 and the additional image setting unit 142 set the print mode of each printed material, and the print modes of the main printed material and the additional printed material are different, the main image and the additional image are displayed to the user as the background image. It is also possible to select whether or not to print at the same position via.

=== Second Embodiment ===
FIG. 8 is a diagram illustrating a short head 311 included in the printer of the second embodiment. In the above-described first embodiment, as shown in FIG. 2B, the printer 1 that transports the continuous medium S under the head 31 in which the short heads 311 are arranged in the paper width direction without stopping is exemplified. Not limited to. In the second embodiment, the operation of ejecting ink from the nozzles while moving one short head 311 shown in FIG. 8 in the movement direction intersecting the nozzle row direction, and transporting the medium (cut sheet) in the nozzle row direction The printer repeats the carrying operation. The operation of forming an image by one movement of the short head 311 in the movement direction is referred to as “pass”. FIG. 8 is a diagram in which the nozzles and the reading sensor 51 are virtually arranged from the upper surface of the short head 311. On the lower surface of the short head 311, nozzle rows for ejecting four colors of ink (YMCK) and white ink (W) are provided. In addition, each nozzle row is configured by 180 nozzles arranged in the transport direction at predetermined intervals D, and numbers are assigned in order from the nozzles on the downstream side in the transport direction (# 1 to # 180). A reading sensor 51 for reading an additional image is provided at a position upstream of the nozzle row in the transport direction. In the embodiment shown in FIG. 8, after printing the additional image, it is necessary to read the medium by carrying it back in the direction opposite to the carrying direction in the figure. On the other hand, the reading sensor 51 may be provided on the downstream side in the conveyance direction of the short head 311. In this case, the medium on which the additional image is printed can be read without being reversely conveyed.

  FIG. 9 is a diagram illustrating a front printing mode and a back printing mode in the printer of the second embodiment. Here, also in the printer of the second embodiment, as shown in FIG. 3, a main printed material in which a main image using four-color ink (YMCK) and a background image of white ink are superimposed, an additional image using four-color ink, and white ink. Suppose you want to print an additional printed material on which the background image is superimposed. Further, when two images are printed in an overlapping manner, it is possible to select either the front printing mode or the back printing mode as shown in FIG. Then, a main image setting unit and an additional image setting unit are provided in the printer (controller), and the print mode of the main print product and the print mode of the additional print product can be set independently. For example, the main image setting unit may determine the print mode of the main printed material based on the user setting as in the flow shown in FIG. Further, the additional image setting unit may determine the print mode of the additional printed material based on whether or not the additional image is read by the reading sensor 51 as shown in the flow of FIG. 6A. However, since the printer of the second embodiment prints an image on a sheet of paper and does not wind up the medium in a roll shape, if the reading sensor 51 does not read, the user may set a print mode, for example.

  Here, an example of printing a background image with a white color adjusted is shown. When a background image is printed using only white ink, the color of the white ink itself that prints the background image becomes the color of the background image. However, even in the case of ink called white ink, the color of white is slightly different depending on the ink material. For this reason, a background image having a color different from the color desired by the user may be printed depending on the white ink used. Depending on the printed matter, a background image having a slight chromatic color instead of simple white color may be desired. When a white medium is used, the white color is slightly different depending on the type of medium even in the white medium. For this reason, when printing a background image on a white medium, the white color of the background image may differ from the white color of the medium. As a result, the background image becomes conspicuous.

  Therefore, it is preferable to print a desired white background image (adjusted white background image) by appropriately using a small amount of color ink (YMCK) together with the white ink. That is, when the background image is printed, at least one color ink among the color inks that can be ejected by the printer 1 may be used. For example, all four color inks may be used. Color inks of colors may be used. In this way, by printing a background image with white ink and color ink, when the white ink has a slight color, the background image is printed with ink that cancels the color, thereby bringing the background image closer to an achromatic color. You can also

  Note that print data for causing the printer 1 to print a desired white background image may be stored in advance by the printer 1 or may be created by a printer driver. When the user selects a desired background image color by looking at the monitor of the printer 1 or the computer screen, print data of the background image corresponding to the selected color may be generated. .

  In the short head 311 of FIG. 9, for simplicity of explanation, the number of nozzles per nozzle row is reduced to 8 (# 1 to # 8), and a nozzle row of four color inks (corresponding to YMCK / first ink). Are drawn as one color nozzle row “Co (corresponding to the first nozzle row)”. The nozzles of the color nozzle row Co are indicated by circles, and the nozzles of the white nozzle row W (corresponding to the second nozzle row) that discharge white ink (corresponding to the second ink) are indicated by triangles. The upper diagram of FIG. 9 is a diagram illustrating printing in the front printing mode. In the printer according to the second embodiment, the position of the used nozzle (discharge nozzle) in the nozzle row is made different depending on the image formed first and the image formed later with respect to a predetermined area on the medium. In the front printing mode, the background image is printed first on a predetermined area of the medium, and the main image or the additional image is printed on the background image. The nozzles # 5 to # 8 (◯) on the upstream side in the transport direction of # 5 to # 8 (Δ) and the color nozzle array Co are used as the background image ejection nozzles, and the transport direction of the color nozzle array Co The nozzles # 1 to # 4 (●) on the downstream side are used as main image discharge nozzles. Note that the image formed by the printing method shown in FIG. 9 is formed by arranging images formed in one pass in the transport direction. Therefore, the medium conveyance amount in one conveyance operation is the image width (4D) formed by half of the nozzle row (four nozzles) in one pass.

  As described above, the nozzles (# 5 to # 8) for forming the background image are nozzles on the upstream side in the transport direction with respect to the nozzles (# 1 to # 4) for forming the main image or the additional image. The background image can be printed first in a predetermined area on the medium, and then the main image or the additional image can be printed on the background image. In the figure on the right side of the upper diagram in FIG. 9, the discharge nozzles for the background image (# 5 to # 8) and the discharge nozzles for the main image or additional image (# 1 to # 4) are shown as one nozzle row. The positional relationship of dots formed in a pass is shown. As can be seen from this figure, for example, a background image was printed on the area A on the medium by the upstream nozzles (# 5 to # 8) of the white nozzle row W and the color nozzle row Co in pass 1. Thereafter, in pass 2, the main image or the additional image is printed on the background image by the downstream nozzles (# 1 to # 4) of the color nozzle row Co.

  On the other hand, as shown in the lower diagram of FIG. 9, in the reverse printing mode, the half nozzles # 1 to # 4 (Δ) on the downstream side in the transport direction in the white nozzle row W and the downstream in the transport direction in the color nozzle row Co. The half nozzles # 1 to # 4 (◯) on the side are used as discharge nozzles for the background image, and the nozzles # 5 to # 8 (●) on the upstream side in the transport direction in the color nozzle row Co are used for the main image. A discharge nozzle is used. By doing so, as shown in the diagram on the right side of the lower diagram of FIG. 9, with respect to the area A on the medium, the upstream nozzles (# 5 to # 8) of the color nozzle row Co in the pass 1 first. After the image or the additional image is printed, a background image is printed on the main image or the additional image by the downstream nozzles (# 1 to # 4) of the white nozzle row W and the color nozzle row Co in pass 2.

  As described above, in a printer that repeats the operation of forming the image by moving the short head 311 in the moving direction and the operation of conveying the medium in the conveying direction, the image is printed first on a predetermined area on the medium. These nozzles are set to the nozzles on the upstream side in the transport direction from the nozzles for printing an image later. By doing so, when two images are overlaid and printed, the image to be formed first and the image to be formed later can be printed in different passes, and the drying time of the image formed first can be ensured. it can. As a result, even when two images are overlaid and printed, bleeding of the image can be suppressed.

  In the second embodiment, as in the first embodiment, the printing mode for the main image and the additional image is set independently. Therefore, the print mode for the main image and the print mode for the additional image may be different. As shown in FIG. 9, if the print mode is different, the main image ejection nozzles are different. For example, when a non-ejection inspection pattern is printed as the additional image, it is necessary to form the non-ejection inspection pattern by a color nozzle that prints the main image. Even if the non-ejection test pattern is not used, the nozzles that are not used to print the main image may increase the viscosity of the ink and may not eject the ink normally. The color nozzles for printing are preferably the same. Therefore, even when the print mode of the main image and the print mode of the additional image are different, the color nozzles for printing the main image and the additional image are made equal. Similarly, the nozzle that prints the background image is added to the nozzle that prints the background image for the main image because the white nozzle that is not used to print the background image for the main image may be dry. It is preferable to use the same nozzle for printing the background image for the image.

  For example, the main printed material is printed in the front printing mode, and the additional printed material is printed in the back printing mode upstream of the main printed material in the transport direction. At this time, in order to print the main printed matter, while conveying the medium from the upstream side in the conveyance direction to the downstream side, as shown in the upper diagram of FIG. 9, the upstream nozzles (# of the white nozzle row W and the color nozzle row Co (# The background image is printed by 5 to # 8), and the main image is printed by the downstream nozzles (# 1 to # 4) of the color nozzle row Co. As a result, the main image can be printed on the background image.

  On the other hand, in order to print the additional printed matter, first, while transporting the medium from the upstream side to the downstream side in the transport direction, the additional image (eg, non-ejection inspection pattern) is transferred to the downstream nozzles (# 1 to # 1) Print according to # 4). Thereafter, since the additional printed matter is in the reverse printing mode, the medium portion on which the additional image is printed is positioned upstream of the upstream nozzles (# 5 to # 8) of the white nozzle row W and the color nozzle row Co. The medium is fed back from the downstream side in the transport direction to the upstream side. Then, while conveying the medium from the upstream side to the downstream side in the conveyance direction, the background image is printed on the additional image by the upstream nozzles (# 5 to # 8) of the white nozzle row W and the color nozzle row Co.

  As a result, even if the print mode of the main print and the print mode of the additional print are different, the nozzle for printing the main image and the nozzle for printing the additional image can be made the same, and the background image for the main image is printed. The nozzle and the nozzle for printing the background image for the additional image can be made the same. By doing so, it is possible to form a non-ejection inspection pattern for confirming non-ejection of the nozzle on which the main image is printed, and the additional printed matter (or main printed matter) at the nozzle used for the main printed matter (or additional printed matter). Can be printed, and an image can be formed with a nozzle that is less likely to cause ejection failure due to ink thickening. In addition, since the medium is transported from the downstream side in the transport direction to the upstream side when the additional printed matter is printed, the position of the additional image and the background image for the additional image is easily shifted. Therefore, similarly to the image of FIG. 7, the margin amount of the background image for the additional image may be larger than the margin amount of the background image for the main image.

  In this way, the position in the transport direction of the nozzles of the white nozzle row W that prints the background image is made equal to the position in the transport direction of the nozzles of the color nozzle row Co that also prints the background image. Then, in order to print the background image, the white ink and the color ink are ejected in the same pass with respect to the predetermined area of the medium. As a result, white ink and color ink are mixed, and the graininess of the background image can be reduced.

  Further, the ratio of the color ink constituting the background image is smaller than the ratio of the white ink. However, in order to reduce the graininess of the color ink in the background image, it is preferable to disperse the dots of the color ink as uniformly as possible. That is, the color ink density (dot density) per unit area of the background image is made smaller than the white ink density (dot density) per unit area of the background image. Therefore, although the ratio of the color ink constituting the background image is smaller than the ratio of the white ink, the number of nozzles of the white nozzle array W and the number of nozzles of the color nozzle array Co used for printing the background image are made equal. That is, the background image is printed using half of the nozzles belonging to the color nozzle row Co. However, the present invention is not limited to this, and the background image may be printed using several nozzles out of the half nozzles of the color nozzle row Co that can be used for printing the background image.

  FIG. 10 is a diagram illustrating another printing method. In the printing method shown in FIG. 9 described above, an image in which an image formed in a single pass is printed in the transport direction, and between raster lines (dot rows along the movement direction) formed in a certain pass, A raster line in another pass is not formed. On the other hand, FIG. 10 shows a printing method in which the printing resolution in the transport direction is increased, and shows a printing method in the front printing mode. As in FIG. 9, in the front printing mode, the background image nozzles (# 5 to # 8) to be printed first are used as the main image or additional image nozzles (# 1 to # 4) to be printed later. Rather than the nozzle on the upstream side in the transport direction. However, unlike FIG. 9, the medium transport amount (4D / 3) in one transport operation is reduced. Therefore, compared with the printing method of FIG. 9, the printing method of FIG. 10 can increase the printing resolution in the transport direction, but the printing time becomes longer. Further, in the printing method of FIG. 10, after the dots for the background image are formed by the white nozzle and the color nozzle (Δ · ○) of pass 1 as in the raster line A shown in the right figure, the color of pass 4 is formed. A nozzle for a main image or an additional image is formed by the nozzle (●). Therefore, compared with the printing method of FIG. 9, in the printing method of FIG. 10, the drying time from when the previous image (background image in FIG. 10) is printed until the subsequent image (main image or additional image) is printed. Can be secured for a long time.

  11A and 11B are diagrams illustrating a printing method in which the nozzles for the background image are different between the main printed material and the additional printed material. For the sake of explanation, the number of nozzles per nozzle row is reduced. As described above, in particular, when a non-ejection inspection pattern is printed as an additional image, it is necessary to form the non-ejection inspection pattern with a nozzle that prints the main image. In addition, nozzles that are not used to print the main image may increase the viscosity of the ink and may not eject ink normally, so the nozzle that prints the main image and the nozzle that prints the additional image must be the same. Is preferred. On the other hand, compared to the main image or the additional image, even if there is a non-ejection nozzle in the nozzle that prints the background image, the image quality is not greatly affected. Therefore, the background image nozzle of the main image and the background image nozzle of the additional image may be different.

  Therefore, when printing the main print and the additional print in different print modes, as shown in FIG. 11A, in the white nozzle row W, 1/3 of the nozzles on the upstream side in the transport direction and 1/3 on the downstream side of the transport direction. These nozzles may be used as background image nozzles, and in the color nozzle row Co, the nozzle in the center 1/3 in the transport direction may be used as the main image and additional image nozzles. For example, FIG. 11A shows the nozzles when the main printed material is printed in the front printing mode and the additional printed material is printed in the back printing mode. First, while conveying the medium from the upstream side to the downstream side, the background image for the main image is printed on the predetermined area on the medium by the nozzles # 9 to # 12 on the upstream side of the white nozzle row W, and then the predetermined area The main image is printed on the background image by the nozzles # 5 to # 8 in the center of the color nozzle row Co. Then, while transporting the medium from the upstream side to the downstream side, an additional image is printed by the nozzles # 5 to # 8 in the center of the color nozzle array Co in another area on the medium, and then the white nozzle array on the additional image. A background image is printed by nozzles # 1 to # 4 on the downstream side of W.

  Thus, even if the printing modes of the main print and the additional print are different, the nozzles of the white nozzle row W on the upstream side (one side) and the downstream side (the other side) of the discharge nozzles of the color nozzle row Co (predetermined direction) By using the nozzle for the background image, it is not necessary to transport the medium in the reverse direction from the downstream side to the upstream side in the transport direction. Even when the background image nozzle of the main image and the background image nozzle of the additional image are different, the background image nozzle is periodically cleaned (eg, flushing), so that the background image nozzle can be removed. Ink droplets can be reliably discharged.

  Further, as shown in FIG. 11B, when the main print and the additional print are printed in different print modes, the position of the color nozzle row Co in which the additional image is printed in the transport direction of the nozzle and the background image of the additional image are printed. The positions of the nozzles in the nozzle row W in the transport direction may be made equal. More specifically, in FIG. 11B, it is assumed that the main printed material is printed in the front printing mode and the additional printed material is printed in the back printing mode, and the medium is transported from the upstream side to the downstream side, and first the upstream side of the white nozzle row W. The background image of the main image is printed by the nozzles # 7 to # 12 on the side half. Next, the main image is printed on the background image of the main image by the nozzles # 1 to # 6 in the downstream half of the color nozzle row Co, and the additional image is printed in another area on the medium. Then, after providing the additional image drying time without conveying the medium, the background image is printed on the additional image by the nozzles # 1 to # 6 in the upstream half of the white nozzle row W. In this way, even if the print modes of the main print and the additional print are different, printing can be performed without transporting the medium from the downstream side to the upstream side in the transport direction.

  In FIGS. 11A and 11B, a background image printed only with white ink is taken as an example, but the present invention is not limited to this. As shown in FIGS. 9 and 10, the background image with the white color adjusted is printed using the nozzles of the color nozzle row Co having the same position in the transport direction as the nozzles of the white nozzle row W for printing the background image. You may do it. In this case, in the printing example of FIG. 11A, the nozzles # 9 to # 12 on the upstream side of the white nozzle row W and the color nozzle row Co serve as the discharge nozzles for the background image of the main image. The 1/3 nozzles # 1 to # 4 on the downstream side of the color nozzle row Co serve as discharge nozzles for the background image of the additional image. In the printing example of FIG. 11B, the nozzles # 7 to # 12 on the upstream side of the white nozzle row W and the color nozzle row Co serve as the discharge nozzles for the background image of the main image, and the white nozzle row W and the color nozzle row. The nozzles # 1 to # 6 on the downstream side of Co serve as discharge nozzles for the background image of the additional image.

  The additional image may have an image quality that allows the user to confirm information related to printing of the main image, and it may not be necessary to adjust the color of the background image of the additional image. In such a case, the background image of the main image may be printed with white ink and color ink in order to adjust the white color, and the background image of the additional image may be printed with only white ink.

  In the above printing example, a color image is printed using only four color inks (YMCK), but the present invention is not limited to this. For example, a color image may be printed using white ink together with four color inks. In this case, in the front printing mode shown in FIG. 9 described above, a color image is printed using the half nozzles (# 1 to # 4) on the downstream side in the transport direction of the color nozzle row Co and the white nozzle row W. On the other hand, in the reverse printing mode, a color image is printed using the half nozzles (# 5 to # 8) on the upstream side in the transport direction of the color nozzle row Co and the white nozzle row W. As described above, the position in the transport direction of the nozzles of the color nozzle row Co for printing the color image is aligned with the position in the transport direction of the nozzles of the white nozzle row W for printing the color image. Then, in order to print a color image, the color ink and the white ink are ejected in the same pass with respect to a predetermined area of the medium. In this way, by printing a color image by adding white ink to the color ink, it is possible to print an image that reproduces a color with high brightness and high saturation.

<Modification>
In the printing examples of FIGS. 9 and 10 of the second embodiment, a background image in which white color is adjusted using white ink and color ink is taken as an example, but the present invention is not limited to this. It may be a background image printed using only white ink. However, in this case, only the background image that is the color of the white ink itself can be printed. Therefore, a background image of a desired color cannot be printed, or the difference between the background image color and the ground color of the medium becomes conspicuous. Therefore, a high-quality background image cannot be printed. Hereinafter, an example of printing when a background image is printed with only white ink will be described.

  FIG. 12 is a diagram illustrating a front printing mode and a back printing mode in the printer of the second embodiment. Here, also in the printer of the second embodiment, as shown in FIG. 3, a main printed material in which a main image using four-color ink (YMCK) and a background image of white ink are superimposed, an additional image using four-color ink, and white ink. Suppose you want to print an additional printed material on which the background image is superimposed. Further, when two images are printed in an overlapping manner, it is possible to select either the front printing mode or the back printing mode as shown in FIG. Then, a main image setting unit and an additional image setting unit are provided in the printer (controller), and the print mode of the main print product and the print mode of the additional print product can be set independently. For example, the main image setting unit may determine the print mode of the main printed material based on the user setting as in the flow shown in FIG. Further, the additional image setting unit may determine the print mode of the additional printed material based on whether or not the additional image is read by the reading sensor 51 as shown in the flow of FIG. 6A. However, since the printer of the second embodiment prints an image on a sheet of paper and does not wind up the medium in a roll shape, if the reading sensor 51 does not read, the user may set a print mode, for example.

  In the short head 311 of FIG. 12, for simplicity of explanation, the number of nozzles per nozzle row is reduced to 8 (# 1 to # 8), and the four-color ink (YMCK) nozzle row is combined into one color nozzle. It is drawn as a column “Co”. The nozzles of the color nozzle row Co are indicated by circles, and the nozzles of the white nozzle row W are indicated by triangles. The upper diagram of FIG. 12 is a diagram illustrating printing in the front printing mode. In the printer according to the second embodiment, the position of the used nozzle (discharge nozzle) in the nozzle row is made different depending on the image formed first and the image formed later with respect to a predetermined area on the medium. In the front printing mode, the background image is printed first on a predetermined area of the medium, and the main image or the additional image is printed on the background image. # 5 to # 8 are discharge nozzles (Δ), and the nozzles # 1 to # 4 on the downstream side in the transport direction in the color nozzle row Co are discharge nozzles (●). Note that the image formed by the printing method shown in FIG. 12 is configured by aligning images formed in one pass in the transport direction. Therefore, the medium conveyance amount in one conveyance operation is the image width (4D) formed by half of the nozzle row (four nozzles) in one pass.

  As described above, the nozzles (# 5 to # 8) for forming the background image are nozzles on the upstream side in the transport direction with respect to the nozzles (# 1 to # 4) for forming the main image or the additional image. The background image can be printed first in a predetermined area on the medium, and then the main image or the additional image can be printed on the background image. In the diagram on the right side of the upper diagram in FIG. 12, the background image ejection nozzles (# 5 to # 8) and the main image or additional image ejection nozzles (# 1 to # 4) are shown as one nozzle row. The positional relationship of dots formed in a pass is shown. As can be seen from this figure, for example, after the background image is printed by the upstream nozzles (# 5 to # 8) of the white nozzle row W in pass 1 for the area A on the medium, the pass 2 Thus, the main image or the additional image is printed on the background image by the downstream nozzles (# 1 to # 4) of the color nozzle row Co.

  On the other hand, as shown in the lower diagram of FIG. 12, in the reverse printing mode, the nozzles # 1 to # 4 on the downstream side in the transport direction in the white nozzle row W are set as ejection nozzles (Δ), and the color nozzle row Co The nozzles # 5 to # 8 on the upstream side in the transport direction are the discharge nozzles (●). By doing so, as shown in the diagram on the right side of the lower diagram in FIG. 12, the upstream nozzles (# 5 to # 8) of the color nozzle row Co in the pass 1 are mainly used for the area A on the medium. After the image or the additional image is printed, the background image is printed on the main image or the additional image by the downstream nozzles (# 1 to # 4) of the white nozzle row W in pass 2.

  As described above, in a printer that repeats the operation of forming the image by moving the short head 311 in the moving direction and the operation of conveying the medium in the conveying direction, the image is printed first on a predetermined area on the medium. These nozzles are set to the nozzles on the upstream side in the transport direction from the nozzles for printing an image later. By doing so, when two images are overlaid and printed, the image to be formed first and the image to be formed later can be printed in different passes, and the drying time of the image formed first can be ensured. it can. As a result, even when two images are overlaid and printed, bleeding of the image can be suppressed.

  In the second embodiment, as in the first embodiment, the printing mode for the main image and the additional image is set independently. Therefore, the print mode for the main image and the print mode for the additional image may be different. As shown in FIG. 12, if the print mode is different, the discharge nozzles of the color nozzle row Co are different. For example, when a non-ejection inspection pattern is printed as the additional image, it is necessary to form the non-ejection inspection pattern by a color nozzle that prints the main image. Even if the non-ejection test pattern is not used, the nozzles that are not used to print the main image may increase the viscosity of the ink and may not eject the ink normally. The color nozzles for printing are preferably the same. Therefore, even when the print mode of the main image and the print mode of the additional image are different, the color nozzles for printing the main image and the additional image are made equal. Similarly, the nozzle that prints the background image is added to the nozzle that prints the background image for the main image because the white nozzle that is not used to print the background image for the main image may be dry. It is preferable to use the same nozzle for printing the background image for the image.

  For example, the main printed material is printed in the front printing mode, and the additional printed material is printed in the back printing mode upstream of the main printed material in the transport direction. At this time, in order to print the main printed matter, the upstream side nozzles (# 5 to # 8) of the white nozzle row W as shown in the upper diagram of FIG. 12 while conveying the medium from the upstream side to the downstream side in the conveyance direction. The background image is printed by the above, and the main image is printed by the downstream nozzles (# 1 to # 4) of the color nozzle row Co. As a result, the main image can be printed on the background image.

  On the other hand, in order to print the additional printed matter, first, while transporting the medium from the upstream side to the downstream side in the transport direction, the additional image (eg, non-ejection inspection pattern) is transferred to the downstream nozzles (# 1 to # 1) Print according to # 4). Thereafter, since the additional printed matter is in the reverse printing mode, the medium is printed in the transport direction so that the medium portion on which the additional image is printed is positioned upstream of the upstream nozzles (# 5 to # 8) of the white nozzle row W. Reverse feed from downstream side to upstream side. Then, the background image is printed on the additional image by the upstream nozzles (# 5 to # 8) of the white nozzle row W while the medium is transported from the upstream side to the downstream side in the transport direction.

  As a result, even if the print mode of the main print and the print mode of the additional print are different, the nozzle for printing the main image and the nozzle for printing the additional image can be made the same, and the background image for the main image is printed. The nozzle and the nozzle for printing the background image for the additional image can be made the same. By doing so, it is possible to form a non-ejection inspection pattern for confirming non-ejection of the nozzle on which the main image is printed, and the additional printed matter (or main printed matter) at the nozzle used for the main printed matter (or additional printed matter). Can be printed, and an image can be formed with a nozzle that is less likely to cause ejection failure due to ink thickening. In addition, since the medium is transported from the downstream side in the transport direction to the upstream side when the additional printed matter is printed, the position of the additional image and the background image for the additional image is easily shifted. Therefore, similarly to the image of FIG. 7, the margin amount of the background image for the additional image may be larger than the margin amount of the background image for the main image.

  FIG. 13 is a diagram illustrating another printing method. In the printing method shown in FIG. 12 described above, an image in which an image formed in one pass is arranged in the transport direction, and between raster lines (dot rows along the movement direction) formed in a certain pass, A raster line in another pass is not formed. On the other hand, FIG. 13 shows a printing method in which the printing resolution in the transport direction is increased, and shows a printing method in the front printing mode. As in FIG. 12, in the front printing mode, the background image nozzles (# 5 to # 8) to be printed first are used as the main image or additional image nozzles (# 1 to # 4) to be printed later. Rather than the nozzle on the upstream side in the transport direction. However, unlike FIG. 12, the medium transport amount (4D / 3) in one transport operation is reduced. Therefore, compared with the printing method of FIG. 12, the printing method of FIG. 13 can increase the printing resolution in the transport direction, but the printing time becomes longer. Further, in the printing method of FIG. 13, after the background image dots are formed by the white nozzle (Δ) in pass 1 as in the raster line A shown in the right figure, the color nozzle (●) in pass 4 is used. Dots for the main image or additional image are formed. Therefore, compared with the printing method of FIG. 12, in the printing method of FIG. 13, the drying time from when the previous image (background image in FIG. 13) is printed until the subsequent image (main image or additional image) is printed. Can be secured for a long time.

=== Other Embodiments ===
Each of the above embodiments is described mainly for a printing system having an ink jet printer, but includes disclosure of a printing mode setting method and the like. The above-described embodiments are for facilitating understanding of the present invention, and are not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and it is needless to say that the present invention includes equivalents thereof.

<Regarding the settings for the back-print mode and front-print mode of additional images>
The setting of the back printing mode or the front printing mode of the additional image may be any that can be set independently of the setting of the main image back printing mode or the front printing mode. The present invention is not limited to the embodiment.

<About images>
In the above-described embodiment, the background image is printed with the white ink. However, the present invention is not limited to this, and the background image may be printed with a color ink other than white (for example, metallic ink). In the first embodiment, the background image is printed only with the white ink. However, the present invention is not limited to this, and the white image and the other color ink are mixed to print the background image with the white color adjusted. Also good. Further, a main image or an additional image may be printed by adding white ink to four-color ink (YMCK).

<Other printers>
In the above-described embodiment, a printer (FIG. 2) that forms an image through a continuous medium under the fixed head 31 and an operation and a single sheet that form an image while moving the head 31 in a direction intersecting the nozzle array direction. Although a printer (FIG. 8) that repeats the operation of transporting paper in the nozzle row direction is taken as an example, it is not limited to this. For example, with respect to continuous paper conveyed to the printing area, an operation of forming an image while the short head 311 as shown in FIG. 8 moves along the conveyance direction of the continuous paper, and a paper width direction intersecting the conveyance direction. It may be a printer that alternately repeats the operation of moving the short head 311 and forms an image, and then transports a medium portion that has not yet been printed to the printing area.

<About printing devices>
The ink ejection method from the nozzle may be a piezo method in which ink is ejected by applying a voltage to the drive element (piezo element) to expand and contract the ink chamber, or a heating element is used to generate bubbles in the nozzle. Alternatively, a thermal method in which ink is ejected by the bubbles may be used.
In the above-described embodiment, ultraviolet curable ink is used. However, the present invention is not limited to this, and water-based ink or organic solvent ink may be used.

  DESCRIPTION OF SYMBOLS 1 Printer, 10 Controller, 11 Interface part, 12 CPU, 13 Memory, 14 Unit control circuit, 141 Main image setting part, 142 Additional image setting part, 20 Conveyance unit, 21A, 21B Conveyance roller, 22 Conveyance belt, 30 Head unit , 31 heads, 40 UV irradiation unit, 41 provisional irradiator, 42 irradiator, 50 detector group, 51 reading sensor, 60 computer.

Claims (6)

A controller capable of executing, as a print mode, a front printing mode for printing an image after printing a background image on a medium and a back printing mode for printing a background image after printing an image on a medium;
The control unit determines the printing mode based on whether the printing surface of the medium is wound on the outer side or the printing surface of the medium is wound on the inner side. Printing device to do. The printing apparatus according to claim 1,
When the printing surface of the medium is wound outside and wound, the control unit sets the printing mode to the front printing mode. The printing apparatus according to claim 1 or 2,
When the printing surface of the medium is wound inside and wound, the control unit sets the printing mode to the back printing mode. The printing apparatus according to any one of claims 1 to 3,
When the image is an image that cannot be read by a sensor, the control unit is wound with the printing surface of the medium positioned outside, or wound with the printing surface of the medium positioned inside, the print mode is determined based on,
When the image is an image read by a sensor, the control unit sets the print mode to print the image in which the background image does not intervene between the sensor and the image. . The printing apparatus according to any one of claims 1 to 4,
The said control part prints the additional image printed in connection with printing of a main image as said image. The front printing mode for printing an image after printing a background image on a medium and the back printing mode for printing a background image after printing an image on a medium can be executed as printing modes.
The printing method, wherein the printing mode is determined based on whether the printing surface of the medium is wound on the outer side or the printing surface of the medium is wound on the inner side .

Images